Ultrasound transducers (40 kHz) as both sources and receivers.

3B30.01 • B+45+10

Ultrasound: Pair of Transducers. The transducers are piezo devices for burglar detection systems. A transducer can operate as both a sound source and sound pick-up. The sensitivity of the transducer falls off sharply for frequencies + or - 40 KHz. This can be seen by trying to talk into the pickup (lower than 40 KHz). Jingling keys have harmonics which extend as high as 40 KHz. Note: Do not treat the transducers roughly. They are fragile. Use low settings for oscillator output, and high scope sensitivity. The transducer will be ruined if input power is > than 100 mw.

Related Demos

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3B30.20 Measurement of speed of sound with microphone, speaker, oscilloscope. 3B30.30 Bell ringing in a jar evacuated with pump. 3B30.50 Breathe helium, voice pitch rises; breathe SF6, voice pitch lowers.

B+45+0 Steel spring pendulum, inverted, vibrates at 10 Hz. B+45+5 Giant tuning fork, barely audible, displayed with stroboscope. B+45+15 Bell ringing in a jar evacuated with pump. B+45+20 Savart's wheel: Toothed wheel and cardboard or air jet. B+45+25 Siren: large, electric motor driven. B+45+30 Compressed air jet blows through spinning disk with holes. B+45+32 Twirling Tube B+45+35 Sprockets on shaft rotate against a card to make sound. B+45+40 Caruga horn: Varigated tube to blow through B+45+41 Feedback from microphone/speaker system. B+45+42 Hoot Tube B+45+45 Galton's whistle: Compressed air whistle. B+45+50 Helmholtz resonators drive radiometer vanes, using tuning forks. B+45+51 Helmholtz Resonators with tuning forks and a candle B+45+55 Casio electronic synthesizer with amp and speaker. B+45+60 Applet: Vibrational Behavior of an Empty Beer Bottle B+45+65 Applet: Vibrational Modes of a Tuning Fork